Search found 44 matches

by David G
Thu Jul 31, 2014 8:04 am
Forum: Software
Topic: Real Time Clock for ZX81
Replies: 9
Views: 5254

Real Time Clock for ZX81

K. Murta wrote a nice app that shows a real-time clock on the ZX81 then proceeds to run a BASIC app in the foreground.

RELOGIO (2004) http://zx81.eu5.org/toddysofte.html

I have adapted it to English. The source code shows the machine language.
by David G
Wed Jul 30, 2014 2:09 am
Forum: FAQs
Topic: Sinclair ZX80 and ZX81 technical specs.
Replies: 1
Views: 6724

Re: Sinclair ZX80 and ZX81 technical specs.

Good question for a FAQ

"Sinclair ZX Specifications" covers the information
http://problemkaputt.de/zxdocs.htm
by David G
Tue Jul 29, 2014 1:45 am
Forum: Development
Topic: ZxList 6, P file to BASIC conversion app
Replies: 29
Views: 9020

Re: ZxList 6, P file to BASIC conversion app

A couple of months ago, I was updating a ZX81 arcade game that hadn't been changed since 1982. It was just minor changes to the machine code, but took a very long time. I originally hand-coded (not using assembly language), and so room had to be found, and patched with two Jumps to the few changed b...
by David G
Tue Jul 29, 2014 12:11 am
Forum: Development
Topic: ZxList 6, P file to BASIC conversion app
Replies: 29
Views: 9020

Re: ZxList 6, P file to BASIC conversion app

Glad to hear it's working! C++ is very small code. The app uses none of optional dynamic linking options of Visual C++ 2008: * No ATL code * No MFC code * No CLR code Just straight Win32 code and C/C++. Unfortunately it stil uses the MSVCR (Microsoft Visual C Runtime), as I understand, for even the ...
by David G
Mon Jul 28, 2014 1:32 pm
Forum: Development
Topic: ZxList 6, P file to BASIC conversion app
Replies: 29
Views: 9020

Re: ZxList 6, P file to BASIC conversion app

I get an error when I try to run this under Windows 7 ( 64 bit) - side by side comparison is incorrect... "side by side comparison is incorrect" is apparently common with Microsoft's 2008 products. The ZXLister was compiled using Visual C++ 2008. Per Microsoft: This issue is caused by a conflict wi...
by David G
Mon Jul 28, 2014 1:09 pm
Forum: Development
Topic: ZxList 6, P file to BASIC conversion app
Replies: 29
Views: 9020

Re: ZxList 6, P file to BASIC conversion app

Attached is the the lastest ZX Lister 6.2 32-bit for Windows. Now feature-complete * dump options succeed on very large REM statements (e.g. 16K apps) - Assembler byte dump statements of machine code REM statements - Hex dump of machine code REM statements * in-memory Variables included, and will ro...
by David G
Sun Jul 27, 2014 7:28 am
Forum: Development
Topic: ZX Floating point to Decimal code in BASIC
Replies: 12
Views: 7161

Re: ZX Floating point to Decimal code in BASIC

In VB81 Xur, the revers function (Decimal to ZXfp), seem to be bugged using "1.5", "1,2" values ! Can your have a look to this code : (Vb81 XuR/ZxToken:ModZXUtil.bas) (I had to type VAL('"1.2") to get the right value!) It appears to work correctly. I ran the posted code in Visual Basic and a sample...
by David G
Sun Jul 27, 2014 6:23 am
Forum: Development
Topic: ZX Floating point to Decimal code in BASIC
Replies: 12
Views: 7161

Re: ZX Floating point to Decimal code in BASIC

For ZX81 floating point, the sign is in the 2nd value byte as shown in the original "ZX81 BASIC Programming" book.

Chapter 27 - Organization of memory
by David G
Sun Jul 27, 2014 6:07 am
Forum: Development
Topic: ZX Floating point to Decimal code in BASIC
Replies: 12
Views: 7161

Re: ZX Floating point to Decimal code in BASIC

For comparison, here is the same BASIC routine converted to C++ known issues: * since it doesn't calculate the FP conversion in the exact same way as ZX81 Basic, it rounds differently. * I haven't tested or implemented E+00 notation for extremely large or extremely small numbers #include <math.h> //...
by David G
Sun Jul 27, 2014 5:35 am
Forum: Development
Topic: ZxList 6, P file to BASIC conversion app
Replies: 29
Views: 9020

Re: ZxList 6, P file to BASIC conversion app

Sorry, I haven't been able to access the forum all week (I get "Error 503 : Service Temporarily Unavailable"). I finally borrowed another computer. Here is the requested 32-bit app. It is not VB, as the free versions of VB are now Visual Basic .NET and are not compatible with Visual Basic. It is a C...